My opinion is that we cannot recreate a natural environment. It's way bigger of a concept than anyone claims to know. You'd need to have an extreme vast knowledge of microbiology (bacteria relationships, viral, fungal, other pathogens and their whole ecosystem web), and nature isn't a closed system. Even puddles are deceptive--puddles often only form because the ground is already full of water and the water table is involved, etc. There is way more water volume involved and way more other factors at play.
I myself do 75-90% water changes every week. Why? Because it isn't just nitrate in our water. It's also pheromones, pathogens, bacteria, etc. We don't have tests for those, so we have no way of knowing how high the levels get inside a sealed glass box. It makes sense to remove as much as you can to keep those levels lower.
"but the fish develop immunity to those pathogen build ups!"
Yes, and no. It's not feasible longterm. You buy new fish, or perhaps something happens and you have to rehome your fish. The new fish added into your environment did not develop immunity to the skyrocketing pathogen levels, so often new fish's immune system gets overwhelmed and they're already compromised from stress to new environment. They are way more likely to fall ill. And on the other hand, your fish who have built immunity can be carriers to a lot of nasty pathogens and transfer those to other people who introduce them to their tanks, and boom disease outbreak (why it's recommended to quarantine, but not everyone does it).
Pheromones can impact growth of fish, especially juveniles. It's why breeders advocate for massive water change schedules. They grow faster with water changes.
Pathogen build up may create an immunity to the localized fish, but the moment an outside stresser happens (power outage causes temperatures to fluctuate, or lack of water flow, or perhaps a fish becomes a bully, or something changes in their environment outside of your control, etc), they become compromised and suddenly are weakened and you now have a disease outbreak "out of nowhere" which spreads fast because the high levels of that pathogen don't need much to take over.
That being said, if someone is changing even a little of their water, it's better than not at all.
And I disagree with completely silencing other people's advice. I don't have to agree with someone, but only allowing one sort of advice can walk a potentially dangerous line.
Am I gonna lose my mind over someone not using fertilizer? Nah. Am I gonna lose my mind over someone who likes one brand of food that I truly hate? Nah. Am I gonna be mad if someone only changes 25% instead of 50%? Nah, at least they're changing something.
There's many ways to do this hobby, but there are ways that are also potentially dangerous to others outside of your own care, or even ways that could potentially backfire hard on you. I'd personally set someone up for easier success than set them on the "easy no maintenance" path that's not going to last longterm or can backfire really bad for them quick.
That's his prerogative on his own forum, just like it's the prerogative of the admins here to make rules--It's a free country and a free internet. Thankfully, it is also my choice not to visit his forum, nor to encourage anyone else to do so.
